The amount of transferred information in telecommunication systems has since long increased rapidly. The information could be of various kinds, e.g. speech, facsimile or video. This constantly increasing amount of transferred information requires fast transportation without unnecessary disturbances. Actions that often causes disturbances in a telecommunication system is loading of memory units, e.g. when changing software version.
The most common method when loading memory units in radio transceivers in a mobile telecommunication system is transferring of software via a control channel. This method is used in various types of mobile telecommunication systems, e.g the D-AMPS system. The D-AMPS system (Digital--Advanced Mobile Phone System) comprises a number of base stations connected to a mobile services switching centre via transmission links, so called PCM-links. A PCM-link comprises a number of traffic channels and one control channel. The control channel is common to all traffic channels and handles the control of the traffic. When reloading a memory unit in a radio transceiver in a base station, the common control channel is used. Using the common control channel when transferring loading data to a memory unit implies that the control channel cannot be used for its normal purpose i.e. handle the traffic distribution. Loading of software via the common control channel is well described in Ericsson document: "CMS 8800 System Survey Training docsient (p. 235-240)" and in the D-AMPS specification "IS-136". Normally the traffic has priority over the loading of data. The loading can therefore be very time consuming, especially when the traffic intensity is high. When the loading has priority, i.e. when consideration is not taken to the normal traffic, the reloading can disturb the normal traffic and when the intensity is very high, the traffic can be totally ruined.
A telecommunication system is known from JP 5/219557 in which a master memory unit contains information common to a number of slave memory units. At power loss in the master memory is unit, information is fetched to the master unit from the slave units, via the air interface. The purpose of the invention according to the Japanese patent is to avoid back-up battery costs.